Biology subjects

Bastien, P.

Publications and source records attributed to Bastien, P..

5 recordsLinked to original sources

bioRxiv2026

Changes of sensory and emotional tactile dimensions with age in self-touch via the application of creams

Touch moderates how we interact with objects, others, and ourselves, where self-touch is particularly important in self-care, although fewer studies have investigated its perception, especially with age. Here, women aged 20-28 and 65-75 years rated how self-applied creams felt on the cheek and forearm, using sensory and emotional descriptors in the Touch Perception Task. Factor analyses uncovered higher tactile dimensions, including Texture, Moisture, Positive Affect, and Negative Affect. Sensory dimensions were more intense in the young group, whereas Positive Affect was stronger in the older group. We then used network and clustering analyses to map how the descriptors interacted. Young participants showed significantly higher connectivity between descriptors, whereas older participants displayed fewer connections, but many became mixed sensory-emotional pairings. Clustering analyses revealed further changes in the tactile groupings with age. We conclude that aging reshapes touch into an emotionally-rich experience, which impacts how interact with ourselves and others.

neuroscience↗

bioRxiv2026

The Nucleoporin MLP1 of the nuclear basket is essential for nuclear integrity and ploidy maintenance in Trypanosoma brucei

Trypanosoma brucei is a divergent eukaryote parasite responsible for neglected tropical diseases in human and animals, sleeping sickness or human African trypanosomiasis and nagana respectively. Besides scientific interest, understanding the specific features of its biology has medical and economical relevance. Nuclear pore complexes (NPCs) are large multiprotein channels embedded in the nuclear envelope that regulate nucleo-cytoplasmic transport. Beyond this role, NPCs also participate in essential nuclear processes such as chromosome segregation, transcription, and cytokinesis. Here, we showed that Myosin-like protein-1 (MLP1) localized to the nuclear basket of NPCs in T. brucei. Silencing of TbMLP1 by RNA interference in T. brucei procyclic cells caused marked defects in parasite growth, severe impairment of messenger RNA export, disorganization of nuclear structure, and pronounced genomic instability. Flow cytometry and FISH analyses revealed abnormal DNA content and a sharp reduction in disomic cells, accompanied by increased numbers of monosomic, trisomic, and polysomic cells, indicating an untolerated aneuploidy. These findings reveal that TbMLP1 links NPC function to multiple key cellular pathways. We provide new insights into the mechanisms that preserve nuclear architecture, nuclear envelope morphology, genome stability, and faithful chromosome segregation, including effects on kinetochore distribution and organization of the mitotic spindle. Author SummaryTrypanosoma brucei is the microscopic parasite responsible for sleeping sickness in humans and nagana in cattle; learning more about its basic biology may help identify weak points that could one day be targeted in new treatments. In this work, we studied a protein called MLP1, which sits at the nuclear pores--the gateways that control what enters and leaves the nucleus. Our findings revealed that MLP1 is essential for ensuring proper movement of messenger RNA, keeping the nucleus stable, and allowing chromosomes to be shared equally when cells divided. In total, we gained new insight into the basic biology of a parasite that remains a major health concern in many regions of the world, showing how a single structural protein can influence many vital processes within it.

microbiology↗

bioRxiv2024

The global dispersal of visceral leishmaniasis occurred within human history

The Leishmania donovani species complex (LdSC) causes visceral leishmaniasis (VL), is present in Africa, Europe, the Middle East, Asia and the Americas, and causes 20-40,000 fatalities per year. Previous analyses concluded that dispersal of this species complex occurred 1-10 million years ago. Using updated methods and data, we show that a ten-thousand year old East African population dispersed globally only within the last 2,000 years, consistent with human migration, war and colonisation as driving factors.

evolutionary biology↗

bioRxiv2023

Quantitative Nanohistology of aging dermal collagen

While the external signs of skin aging have been well-defined throughout history, much less is known about aging within the ultrastructure of our skin. Our skin, the largest organ in our body, is structured by collagen through fibrils or large sheets. With the increased use of nanometrology tools in histology, it is now possible to explore how the aging process affects collagen at its most fundamental level, the collagen fibril. Here, we show how atomic force microscopy-based quantitative nanohistology can differentiate skin from different age groups and anatomical sites. Following the definition of specific collagen biomarkers at the nanoscale, we used a segmentation approach to quantify the prevalence of 4 structural biomarkers over a dataset of 42,000 images (30 donors) complemented by extensive nanomechanical analyses (30,000 indentation curves) on histological sections. Our results demonstrate that specific age-related collagen fingerprints could be found when comparing the % prevalence of each marker between the papillary and reticular dermis. A case of abnormal biological aging validated our markers and nanohistology approach. This first extensive study focusing on defining signs of dermal aging at the nanoscale proves we are all unique to our dermal collagen ultrastructure.

biophysics↗

bioRxiv2019

Original research. Inhibition of Polymerase Chain Reaction: Pathogen-Specific Controls are better than Human Gene Amplification

PCR inhibition is frequent in medical microbiology routine practice and may lead to false-negative results; however there is no consensus on how to detect it. Pathogen-specific and human gene amplifications are widely used to detect PCR inhibition. We aimed at comparing the value of PCR inhibitor detection using these two methods. We analysed Cp shifts ({Delta}Cp) obtained from qPCRs targeting either the albumin gene or the pathogen-specific sequence used in two laboratory-developed microbiological qPCR assays. 3152 samples including various matrixes were included. Pathogen-specific amplification and albumin qPCR identified 62/3152 samples (2.0 %), and 409/3152 (13.0%) samples, respectively, as inhibited. Only 16 samples were detected using both methods. In addition, the use of the Youdens index failed to determine adequate Cp thresholds for albumin qPCR, even when we distinguished among the different sample matrixes. qPCR targeting the albumin gene therefore appears not adequate to identify the presence of PCR inhibitors in microbiological PCR assays. Our data may be extrapolated to other heterologous targets and should discourage their use to assess the presence of PCR inhibition in microbiological PCR assays.

microbiology↗